A General Coercivity Model for Soft Magnetic Materials

Abstract:

The effect of crystalline imperfections (as for instance, grain size, inclusions and dislocations) on the coercivity of soft magnetic materials is additive. This only can be explained by an Energy Balance Model. By another hand, the angular dependence of the coercivity only can be explained with a Force Balance Model. Thus both models, Energy Balance and Force Balance have to be invoked for the construction of a general model. The effect of dislocations on the coercivity can be treated as short range magnetostrictive effect. The effect of inclusions needs the consideration of the global magnetostatic energy of the system. The dependence of the coercivity with the grain size can also be explained analyzing the magnetostatic energy. The idea of pinning of domain walls by crystalline defects is reformulated, and it is shown that the coercivity increase due to crystalline defects is principally caused by variations of the magnetostatic energy in the system.

• Periodical: Materials Science Forum (Volumes 727-728)
• Pages: 157-162
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.727-728.157
• Online since: August 2012
• Authors: Marcos Flavio de Campos
• Keywords: Coercivity, Dislocation, Grain Size, Hysteresis

References

[1] E. Adler and H. Pfeiffer: Trans. Magn. Vol MAG-10 (1974), p.172.

[2] K.H. Stewart: Ferromagnetic Domains. Edited by Cambridge at University Press. London, (1954).

[3] S. Chikazumi: Physics of Magnetism. Edited by Robert E. Krieger Pub. Company. Malabar, Florida. Reprint (1984).

[4] M.F. de Campos: Materials Science Forum Vols. 660-661 (2010), p.284.

[5] M.F. de Campos: Materials Science Forum Vols. 530-531 (2006), p.146.

[6] M.F. de Campos, J.C. Teixeira and F.J.G. Landgraf: J. Magn. Magn. Mat. Vol. 301 (2006), p.94.

[7] A. Mager: Ann. Phys. Lpz. Vol. 11 (1952), p.15.

[8] M.F. de Campos, M. Emura and F.J.G. Landgraf: J. Magn. Magn. Mat. Vol. 304 (2006), p. e593.

[9] L.J. Dijkstra and C. Wert: Phys. Rev. Vol. 79 (1950), p.97.

[10] E.F. Monlevade, M. F. de Campos, F. A. Franco, J. Capo-Sanchez, H. Goldenstein and L.R. Padovese: IEEE Trans. Magn. (2012).

DOI: 10.1109/tmag.2011.2173666

[11] J.P. Hirth: Metallurgical Transactions A Vol. 16A (1985), p. (2085).

[12] J.D. Verhoeven: Fundamentals of Physical Metallurgy. Edited by John Willey & Sons. New York, (1975).

[13] E.C. Stoner and E.P. Wohlfarth: Phil. Trans. Royal Soc. London Vol. A240 (1948), p.599.

[14] L.J. Swartzendruber, G.E. Hicho, H.D. Chopra, S.D. Leigh, G. Adam and E. Tsory: J. Appl. Phys. Vol. 81 (1997), p.4263.

[15] C.K. Hou: IEEE Trans. Magnetics Vol. 30 (1994), p.212.

[16] M.F. de Campos, M.J. Sablik, F.J.G. Landgraf, T.K. Hirsch, R. Machado, R. Magnabosco, C. J. Gutierrez and A. Bandyopadhyay: J. Magn. Magn. Mater. Vol. 320 (2008), p. e377-e380.

DOI: 10.1016/j.jmmm.2008.02.104

[17] M.C.A. da Silva, M.F. de Campos, F.J.G. Landgraf and I.G.S. Falleiros, unpublished.

[18] W.H. Hosford. Physical metallurgy. 2nd Edition (CRC Press, Taylor and Francis. 2010).

[19] K.J. Overshott: IEE Proceedings A, Vol. 138, (1991), p.22.